Method for controlling a modulating filling valve and filling device for performing such method

Abstract

The invention relates to a method for controlling a modulating valve during a filling operation on a plurality of receptacles to fill them with a pourable product. The valve includes a shutter for closing or opening an outflow passage of the valve, designed to control the filling of receptacles. The method includes measuring the flowrate of the pourable product passing through the valve; measuring the position of the shutter along the axis; and controlling the position of the shutter as a function of the desired flowrate. The method also includes defining an initial table containing at least the flowrate and position values measured prior to a first filling during the same filling operation; and updating the table with flowrate and position values measured during fillings subsequent to the first filling during the same filling operation. The controlling step is carried out as a function of the table.

1 . A method for controlling a modulating valve ( 5 ) during a filling operation carried out, without interruptions of production, on a plurality of receptacles ( 2 ) for filling them with a pourable product under pressure, said valve ( 5 ) comprising a shutter ( 8 ) movable along an axis (A) for closing or opening in a variable manner an outflow passage of the valve ( 5 ) itself designed to control the filling of said receptacles ( 2 ) with said pourable product;
 said method comprising the steps of   measuring the flowrate of said pourable product passing through said valve ( 5 ) by means of a flowmeter ( 25 );   measuring the position of said shutter ( 8 ) along said axis (A) by means of a position sensor ( 26 );   controlling said position of said shutter ( 8 ) as a function of the desired flowrate: method further comprising:   defining an initial table (T 1 ; T 2 ) containing at least the flowrate and position values prior to a first filling of said receptacles ( 2 ) during said filling operation;   updating said table (T 1 ; T 2 ) with flowrate and position values during fillings subsequent to said first filling during said filling operation; and   measuring the pressure of said pourable product by means of a pressure sensor ( 28 ), wherein:   the controlling step is carried out as a function of said table (T 1 ; T 2 ),   the defining step comprises associating said flowrate and position values to respective pressure values in the measuring step, and   the updating step is carried out by including in said table (T 2 ) said pressure values in the measuring step and associating step, respectively with said flowrate and position values.   
     
     
         2 . The method according to  claim 1 , wherein said controlling step is carried out as a function of the initial table (T 1 ; T 2 ) defined in the defining step, while said first filling is being carried out, and according to the table (T 1 ; T 2 ) updated in the updating step, while said fillings subsequent to said first filling are being carried out. 
     
     
         3 . The method according to  claim 1 , wherein the defining step comprises:
 measuring the flowrate of said pourable product passing through said valve ( 5 ) as a function of at least a position of said shutter ( 8 ) prior to said first filling; and   storing in said initial table (T 1 ; T 2 ) the, flowrate value measured in the measuring step and said at least one position of said shutter ( 8 ).   
     
     
         4 . The method according to  claim 3 , wherein said measuring and storing steps are repeated for more positions of said shutter ( 8 ). 
     
     
         5 . (canceled) 
     
     
         6 . A filling device ( 1 ;  30 ) comprising a modulating valve ( 5 ) having a shutter ( 8 ) movable along an axis (A) for closing or opening in a variable manner an outflow passage of the valve ( 5 ) itself designed to control the filling of receptacles ( 2 ) with a pourable product under pressure;
 said filling device ( 1 ;  30 ) further comprising:   a flowrate sensor ( 25 ) configured for measuring the flowrate of said pourable product passing through said valve ( 5 ) and for generating a flowrate signal (Q) correlated with the measured flowrate;   a position sensor ( 26 ) configured for measuring the position of said shutter ( 8 ) along said axis (A) and for generating a position signal (L) correlated with the measured position; and   a control unit ( 27 ) configured for receiving said flowrate (Q) and position (L) signals and controlling the positioning of said shutter ( 8 ) along said axis (A) as a function of said flowrate (Q) and position (L) signals;   a pressure sensor ( 28 ) configured for measuring the pressure of said pourable product inside a tank ( 3 ) and for generating a pressure signal (P) related to the pressure measured,   wherein the positioning of said shutter ( 8 ) along said axis is commanded by said control unit ( 27 ) as a function of a table (T 1 ; T 2 ), which, at the start of a filling operation carried out, without interruptions of production, on a plurality of receptacles ( 2 ), contains at least the flowrate and position values measured respectively by said flowrate sensor ( 25 ) and by said position sensor ( 26 ) prior to a first filling of said receptacles ( 2 ) during said filling operation, and subsequently is updated with the flowrate and position values measured respectively by said flowrate sensor ( 25 ) and by said position sensor ( 26 ) during respective fillings subsequent to said first filling, and   wherein said control unit ( 27 ) is further configured for associating said flowrate and position values to respective pressure values measured by the pressure sensor ( 28 ).   
     
     
         7 . The device according to  claim 6 , wherein said valve ( 5 ) receives said pourable product from the tank ( 3 ) pressurised through a duct ( 4 ); said valve ( 5 ) comprising a hollow body ( 6 ) coaxial to said axis (A) and defining a flow channel ( 7 ) for said pourable product housing said shutter ( 8 );
 said flowrate sensor ( 25 ) being arranged at said duct ( 4 ) and measuring the flowrate passing through said duct ( 4 );   said position sensor ( 26 ) being arranged in correspondence with said shutter ( 8 ).   
     
     
         8 . (canceled) 
     
     
         9 . The device according to  claim 6 , further comprising an electromagnetic actuator ( 22 ) configured for receiving a command signal (C) from said control unit ( 27 ) correlated with said table (T 1 ; T 2 ) and for controlling the movement of said shutter ( 8 ) within said channel ( 7 ). 
     
     
         10 . The method according to  claim 2 , wherein the defining step comprises:
 measuring the flowrate of said pourable product passing through said valve ( 5 ) as a function of at least a position of said shutter ( 8 ) prior to said first filling; and   storing in said initial table (T 1 ; T 2 ) the flowrate value measured in the measuring step and said at least one position of said shutter ( 8 ).   
     
     
         11 . The device according to  claim 7 , further comprising an electromagnetic actuator ( 22 ) configured for receiving a command signal (C) from said control unit ( 27 ) correlated with said table (T 1 ; T 2 ) and for controlling the movement of said shutter ( 8 ) within said channel ( 7 ). 
     
     
         12 . The device according to  claim 8 , further comprising an electromagnetic actuator ( 22 ) configured for receiving a command signal (C) from said control unit ( 27 ) correlated with said table (T 1 , T 2 ) and for controlling the movement of said shutter ( 8 ) within said channel ( 7 ).